Ethernet

Ethernet is defined as a trademark for a system that coordinates the components of a local area network.

An example of Ethernet is the cable system that connects the computer network of a small business office.

Ethernet

noun

a system for connecting and coordinating the components of a local area network

Origin of Ethernet

ether (prob. sense ) + net(work)

Ethernet

A trademark for a LAN protocol.

Ethernet

Noun

(plural ethernets)

Alternative capitalization of Ethernet.

ethernet - Computer Definition

Robert M. Metcalfe and his associates at the Xerox Palo Alto Research Center (Xerox PARC) first developed both the concept of a local area network (LAN) and the enabling technology.That first network originally was known as the Altos Aloha Network, because it connected Altos computers through a network based on the University of Hawaii's AlohaNet packet radio system technology. Subsequently (1973), it was renamed Ethernet, from luminiferous ether, the omnipresent passive medium once theorized to pervade all space and to support the propagation of electromagnetic energy.The original Ethernet supported a transmission rate of 2.94 Mbps over coaxial cable. Xerox commercialized the technology, renaming it the Xerox Wire. Gordon Bell, vice president of engineering at Digital Equipment Corporation (DEC, subsequently acquired by Compaq, which later merged with Hewlett-Packard), hired Metcalfe as a consultant in 1979 specifically to develop a LAN network technology that would not conflict with the Xerox patent. Metcalfe brought DEC, Intel, and Xerox together to form into a joint venture known as DIX, which improved the technology, increasing the bandwidth to 10 Mbps and reverting to the name Ethernet.The technology quickly became a de facto standard. In February 1980, the IEEE established Project 802 to develop a set of LAN standards. In December 1982, the first standard was published and circulated as IEEE 802.3, which actually is a variation on the now obsolete Ethernet standard. Although the two do not interoperate, the terms 802.3 and Ethernet are used interchangeably in informal conversation. Ethernet has evolved considerably since 1980. The signaling rate has increased from 10 Mbps to 100 Mbps, 1 Gbps, and 10 Gbps. The original 10Base5 specification for coaxial cable has given way to 10/100/1000Base-T specifications for twisted pair, and various 10GBase-XX specifications for optical fiber. Relatively unchanged have been the frame format and the protocols for medium access control (MAC), which include carrier sense multiple access with collision detection (CSMA/CD) and carrier sense multiple access/collision avoidance (CSMA/CA).The Ethernet frame, as illustrated in Figure E-3, is formatted as follows:

In 1985, the U.S. Institute of Electrical and Electronic
Engineers (IEEE) developed standards for Local Area Networks (LANs) called the
IEEE 802 standards. These standards presently form the basis of most networks.

One of the IEEE 802 standards—the IEEE 802.3—is known as
“Ethernet,” the most prevalently used LAN
technology around the globe. Ethernet was designed by the Xerox Corporation in
1972, and in its simplest form it used a passive bus operated at 10 Mbps. A
50-Ohm coaxial cable connected the computers in the network.

Though a single LAN can have as many as 1,024 attached
computer systems, in practice most LANs have far fewer than this. Typically,
one or several coaxial cable pieces are joined end-to-end to form the bus, also
known as an “Ethernet cable segment.” Each Ethernet cable segment is terminated
at both ends by 50-Ohm resistors and is usually grounded at one end for safety
reasons. Thus, computers attach to the cable using network interface cards
and/or transceivers.

Since its birth, Ethernet has grown to much higher speeds.
For example, at the start of 2004, 10 GBit/s (standardized as 802.3ae) network
adapters were introduced. Furthermore, the once error-prone, single-cable bus
architecture has evolved into a notable error-reduced star topology using hubs
and switches.

The global standard for cabling computers together in a network. All new computers come with Ethernet, and old machines can be retrofitted via USB or an Ethernet card.
Almost every reference to "network," "network ready," "LAN," "LAN connection" or "network card" implies Ethernet. Defined by the IEEE as the 802.3 standard, the Ethernet access method is used to connect computers in a company or home network as well as to connect a single computer to a cable modem or DSL modem for Internet access. See LAN.
New homes and buildings may be wired for Ethernet, not only to provide an information network but also to provide an electrical source for lighting (see PoE lighting).
Ethernet Is Wired - Wi-Fi Is Wireless
Ethernet uses cables to connect devices; however, its wireless counterpart is "Wi-Fi," and both wired and wireless operation is commonplace in companies and at home. Ethernet is also built into home theater equipment and many home appliances. See Wi-Fi and wireless router.
From 10 to 10,000 Megabits Per Second
A 10/100 Ethernet port supports 10 Mbps and 100 Mbps. A 10/100/1000 port adds Gigabit Ethernet at 1,000 Mbps (1 Gbps). New computers have at least 10/100 and often 10/100/1000 connections and negotiate with each other to transmit at the highest common speed. Wide area network backbones (WANs) may employ 10 Gigabit Ethernet (10,000 Mbps), but there is no such thing as a 10/100/1000/10000 port on any product (see 10 Gigabit Ethernet).
Ethernet Frames
Ethernet transmits variable length frames up to 1500 bytes in length, each containing a header with the addresses of the source and destination stations and a trailer that contains error correction data. Higher-level protocols, most notably IP, break apart longer messages into the required frame size (see Internet protocol and MTU). Ethernet is a data link protocol that uses a collision detection method. For more details, see CSMA/CD and data link protocol.
History
Invented by Robert Metcalfe and David Boggs at Xerox PARC in 1973, Ethernet first ran at just under 3 Mbps. Metcalfe joined Digital Equipment Corporation where he facilitated a joint venture with Intel and Xerox to collaborate further, and Ethernet Version 1 was finalized in 1980. In 1983, the IEEE approved the Ethernet 802.3 standard. See 100Base-T, Gigabit Ethernet, 10 Gigabit Ethernet and Ethernet switch.
ETHERNET CABLE MAXIMUM LENGTHS (From Device to Switch)
TWISTED PAIR (Metal Wires)
10Base-T 328 ft/100 m
100Base-T 328 ft/100 m
1000Base-T 328 ft/100 m
OPTICAL FIBER
MM=multimode fiber SM=singlemode
FOIRL MM .6 mi/1 km
10Base-FL MM 1.2 mi/2 km
100Base-FX MM 1.2 mi/2 km
100Base-FX SM 6 mi/10 km

Ethernet Is a Star Topology

All computers connect to a central switch that lets each sender/receiver pair transmit at full speed (10, 100 or 1000 Mbps). Spare telephone wires are sometimes used, but often at lower speeds. For earlier topologies, see 10Base5 and 10Base2. See Ethernet switch, cable categories and twisted pair.

Ethernet Switch

This Omnitron switch has 16 10/100 ports and, like all Ethernet switches, automatically adjusts to the highest common speed between the sender and receiver.